Process for production of benzonitrile and benzyl alcohol

Abstract

A process for producing a fluorinated benzonitrile comprising hydrogenolyzing a fluorinated dicyanobenzene substituted with 1 to 4 fluorine atoms and having the remainder which may be substituted with a chlorine atom in the presence of a catalyst to cause hydrodecyanation of only the cyano group of one side and a process for producing a fluorinated benzyl alcohol comprising reducing the fluorinated benzonitrile and hydrolyzing the fluorinated benzonitrile and reducing the resultant corresponding fluorinated benzoic acid to convert the cyano group to a hydroxymethyl group.

We claim: 
     
       1. A process for producing a fluorinated benzonitrile comprising the step of: hydrogenolyzing a fluorinated dicyanobenzene substituted with 1 to 4 fluorine atoms and having the remainder which may be substituted with a chlorine atom in the presence of at least one metal catalyst selected from the group consisting of metals of Group VIII, Group IX, and Group X of the Periodic Table with or without supplying hydrogen gas using an aromatic compound having hydrogen at its α-position as a source of hydrogen at a temperature from room temperature to about 400° C. so as to cause hydrodecyanation of only the cyano group.   
     
     
       2. A process for producing a fluorinated benzonitrile as claimed in claim 1, wherein the catalyst is at least one metal catalyst selected from the group consisting of metals of Group VIII, Group IX, and Group X of the Periodic Table. 
     
     
       3. A process for producing a fluorinated benzonitrile as claimed in claim 1, wherein the fluorinated dicyanobenzene is tetrafluoroterephthalonitrile. 
     
     
       4. A process for producing a fluorinated benzonitrile as claimed in claim 1, wherein a monoalkyl substituted benzene is used as the solvent. 
     
     
       5. A process for producing a fluorinated benzonitrile as claimed in claim 1, wherein the hydrodecyanation reaction is carried out with or without supplying hydrogen gas using an aromatic compound having hydrogen at its α-position as a source of hydrogen. 
     
     
       6. A process for producing a fluorinated benzyl alcohol having the formula (I): ##STR13## wherein a and b independently represent 1, 2, 3, or 4 and c represents 0, 1, or 2 comprising the steps of: hydrodecyanating only one of the cyano groups of a fluorinated dicyanobenzene having the formula (II) ##STR14## wherein a, b, and c are defined as above, to produce a fluorinated benzonitrile having the formula (III): ##STR15## wherein a, b, and c are as defined above and then converting the cyano group of the fluorinated benzonitrile to a hydroxymethyl group.   
     
     
       7. A process for producing a fluorinated benzyl alcohol as claimed in claim 6, wherein the process comprises hydrogenolyzing the fluorinated dicyanobenzene having the above formula (II) in the presence of a catalyst to hydrodecyanate only one cyano group, whereby the fluorinated benzonitrile having the formula (III) is produced, and then reducing the resultant fluorinated benzonitrile or hydrolyzing the resultant fluorinated benzonitrile and reducing the resultant corresponding fluorinated benzoic acid thereby to convert the cyano group to a hydroxymethyl group. 
     
     
       8. A process for producing a fluorinated benzyl alcohol as claimed in claim 7, wherein the catalyst is at least one metal catalyst selected from the group consisting of metals of Group VIII, Group IX, and Group X of the Periodic Table. 
     
     
       9. A process for producing a fluorinated benzyl alcohol as claimed in claim 6, wherein the fluorinated dicyanobenzene is tetrafluoroterephthalonitrile. 
     
     
       10. A process for producing a fluorinated benzyl alcohol as claimed in claim 6, wherein the fluorinated benzonitrile having the formula (III) is reduced to a fluorinated benzaldehyde having the formula: ##STR16## wherein a, b, and c are as defined above, and the aldehyde group of the fluorinated benzaldehyde is then reduced to a hydroxymethyl group. 
     
     
       11. A process for producing a fluorinated benzyl alcohol as claimed in claim 10, wherein the cyano group of the fluorinated benzonitrile having the above formula (III) is reduced to a hydroxymethyl group by a single stage reaction without isolating the fluorinated benzaldehyde. 
     
     
       12. A process for producing a fluorinated benzyl alcohol as claimed in claim 6, wherein tetrafluoroterephthalonitrile is used as a starting material and only the cyano group of one side is hydrodecyanated to produce 2,3,5,6-tetrafluorobenzonitrile, followed by converting the cyano group of the 2,3,5,6-tetrafluorobenzonitrile to a hydroxymethyl group so as to produce 2,3,5,6-tetrafluorobenzyl alcohol. 
     
     
       13. A process for producing a fluorinated benzyl alcohol as claimed in claim 6, wherein a monoalkyl substituted benzene is used as a solvent of the hydrodecyanation reaction. 
     
     
       14. A process for producing a fluorinated benzyl alcohol as claimed in claim 6, wherein the hydrodecyanation reaction is carried out with or without supplying hydrogen gas using an aromatic compound having hydrogen at its α-position as a source of hydrogen. 
     
     
       15. A process for producing a fluorinated benzyl alcohol comprising the step of: reducing a fluorinated benzonitrile substituted with 1 to 4 fluorine atoms and having the remainder which may be substituted with a chlorine atom or hydrolyzing the fluorinated benzonitrile and reducing the resultant corresponding fluorinated benzoic acid to convert the cyano group to a hydroxymethyl group.   
     
     
       16. A process for producing a fluorinated benzyl alcohol as claimed in claim 15, wherein the fluorinated benzonitrile is 2,3,5,6-tetrafluorobenzonitrile.